Amino acids are small molecules with a carboxylic acid group and an amine group attached to the α carbon atom. amino acids are known as the building blocks of proteins. Amino acid chart includes the 20 amino acids along with their universal genetic codes, properties, abbreviations and structures.
Question 1: Amino acids are mostly synthesised from-
(a) Fatty acids
(b) Mineral salts
(c) a-ketoglutaric acid
(d) Volatile acids
Answer: Option c) a-ketoglutaric acid
Explanation: Amino acids are mostly synthesized from a-ketoglutaric acid. These are also known as precursors of amino acids. a-ketoglutaric acid is keto-derivative of glutaric acid.
Question 2: The first amino acid of any polypeptide chain in eukaryotes is-
Answer: Option b) Methionine
Explanation: The first amino acid in any polypeptide chain of a eukaryote is always methionine. This is because AUG is the start codon that codes for methionine in eukaryotes.
Question 3: The simplest amino acid is
Answer: Option a) Glycine
Explanation: The simplest amino acid, commonly found in animal proteins is glycine. It is a non-essential amino acid produced naturally by living bodies and plays a key role in the synthesis of important bio-compounds and proteins.
Question 4: Which of the following amino acids contain sulfur?
a) Cysteine and methionine
b) Methionine and threonine
c) Cysteine and threonine
d) Cysteine and serine
Answer: Option a) Cysteine and methionine
Explanation: Methionine and cysteine are two amino acids that contain sulfur in its side chain. Methionine is nonpolar and hydrophobic but Cysteine ionizes to yield thiolate anion.
Question 5: Which of the following are acidic amino acids –
a) Arginine and glutamate
b) Aspartate and asparagine
c) Aspartate and lysine
d) Aspartate and glutamate
Answer: Option d) Aspartate and glutamate
Explanation: aspartic acid or aspartate (Asp) and glutamic acid or glutamate (Glu) are two amino acids which have acidic side chains as their side chains have carboxylic acid groups.
Question 6: Which of the following amino acids have hydroxyl groups -
a) Serine and alanine
b) Alanine and Valine
c) Serine and threonine
d) Valine and Isoleucine
Answer: Option c) Serine and threonine
Explanation: Serine and threonine are two amino acids which contain aliphatic hydroxyl groups. Hydroxyl amino acids are polar and hydrophilic in nature.
Question 7: Which of the following are positively charged basic amino acids?
a) Lysine and arginine
b) Lysine and asparagine
c) Glutamine and arginine
d) Lysine and glutamine
Answer: Option a) Lysine and arginine
Explanation: Arginine (Arg) and lysine (Lys) contain nitrogen in their side chain and resemble basic ammonia. They tend to bind protons, gaining a positive charge in the process.
Question 8: Amino acids containing aromatic side chain are-
a) tryptophan, asparagine, tyrosine
b) tryptophan, threonine, tyrosine
c) phenylalanine, tryptophan, serine
d) phenylalanine, tryptophan, tyrosine
Answer: Option d) phenylalanine, tryptophan, tyrosine
Explanation: A side chain is aromatic when it contains an aromatic ring system. phenylalanine, tryptophan, tyrosine have aromatic side chains.
Question 9: Which one of the following is the non essential amino acid?
Answer: Option c) Serine
Explanation: Nonessential Amino Acids are produced by our bodies and are not taken as food supplements. Serine is a nonessential amino acid.
Question 10: Amino acids with the non polar aliphatic ‘R’ group are-
a) Glycine, alanine, leucine
b) Serine, threonine, cysteine
c) Lysine, arginine, histidine
d) Phenylalanine, tyrosine and tryptophan
Answer: Option a) Glycine, alanine, leucine
Explanation: Amino acids with non-polar aliphatic R groups are Glycine, alanine, leucine These amino acids include hydrocarbon R chain and are nonpolar and hydrophobic.er.
The codons can be read using the amino acid chart-
Find the codon’s first base in the first column of the chart, staying in this row, Now, find the second base in the middle of the chart, again staying in this box, locate the third base in the far right column, this gives us the amino acid that matches the mRNA codon.
Amino acids are small molecules with a carboxylic acid group and an amine group attached to the α carbon atom. amino acids are known as the building blocks of proteins. Each protein molecule is made up of different combinations of 20 amino acids.
Examples of amino acids include histidine, lysine, valine.
The 21 different amino acids our bodies need are:
Free amino acids are single amino acids which are already in a pre-digested form and are ready to be used by our body. Free amino acids are not bound to any proteins and can be instantly absorbed by the body.